drowsy vs having spring fever

drowsy

adj

  • Causing someone to fall sleep or feel sleepy; lulling; soporific. 

  • Dull; stupid. 

  • Boring. 

  • Inclined to drowse; heavy with sleepiness 

having spring fever

How often have the words drowsy and having spring fever occurred in a corpus of books? (source: Google Ngram Viewer )